Estimating Plumbing and Electrical Issues

[Andrew Adam]

There was a 4-plex in my area listed for 75k, I called 4 days after it was listed on the MLS and the Realtor told me they closed that morning. A month or two has gone by and it was still on the MLS, yesterday it dropped 25k to only 50K!

My Realtor told me that he spoke with the selling Realtor and the family is trying to get rid of it as they are splitting an estate. He also said that the original buyer backed out after the extensive repair list that the inspector came back with. 

I heard there were some major plumbing and electrical issues at the top of the list. I am guessing maybe 20k but I have no prior experience to base that off of. It is fully rented currently so at this price it should be cash flowing nicely. 

How much should I estimate/budget for those repairs?

Thoughts or Suggestions?